If you aren't keeping up at 80%, I don't think 90% is going to make much difference at this point. There is a good chance that algae has started to grow and is fighting against you. The longer you put it off, the worse it will be. If I were in your shoes, I would SLAM the pool and get it over with.
As for the tiny bubbles, you might not be able to see them at the return jets, but if your salt cell is transparent, you should be able to see them there. They are so tiny that they often just look like cloudiness coming out of the cell.
As for the tiny bubbles, you might not be able to see them at the return jets, but if your salt cell is transparent, you should be able to see them there. They are so tiny that they often just look like cloudiness coming out of the cell.